awful (esp. BrE), big, considerable (esp. BrE), dreadful (esp. BrE), great, huge, major, massive, nasty, real, rude, terrible, tremendous
Drivers could be in for a nasty shock when they see the cost of renewing their insurance policies.

absolute, complete, pure, total, utter (esp. AmE)
mild, slight
first, initial
Once the initial shock had worn off, I got to like my new hairstyle.

sudden
economic, emotional
culture
It was a bit of a culture shock when I first came to this country.

sticker (AmE)
Customers may experience sticker shock when they see the prices of the new SUVs (= they may be shocked by the prices).

come as
feel, get, have, receive
She felt shock that he would be capable of such an act.
I got a terrible shock when I saw him.

give sb
be in for
If you think it's going to be easy, you're in for a shock!

die of (informal)
I nearly died of shock when your mother appeared.

get over, recover from
express
feign
imagine
Imagine my shock when I saw them kissing!

tactics
value
The scene was clearly added for shock value.

jock (informal, esp. AmE)
radio shock jock Howard Stern

troops
wave
The news sent shock waves through the financial markets. (figurative)

defeat, departure, exit (all BrE,sports)
United suffered a shock defeat to Norwich.

result, victory, win (all BrE,sports)
announcement, decision, resignation (all BrE)

in shock
She looked around in shock.

with a shock
She realized with a sudden shock that she was being followed.

shock at, shock on
her shock on seeing him with another woman

shock to
This news came as a great shock to me.

a bit of a shock, quite a shock, something of a shock
in a state of shock
I think I'm still in a state of shock.

a feeling of shock, a sense of shock
shock horror (BrE,humorous)
The article reports on a celebrity who—shock horror—has gained weight!

the shock of your life (informal)
I got the shock of my life when she told me she was pregnant.

a shock to the system (informal)
The low salaries came as something of a shock to her system.

massive (esp. BrE), severe
mild
He gave himself a mild electric shock while changing a light bulb.

painful
electric (less often electrical)

get, receive
give sb
administer
The guards would administer electric shocks to the inmates.

therapy

deep, severe
mild
delayed (esp. BrE)
anaphylactic
shell
soldiers suffering from shell shock

be in, be suffering from, suffer
He was in deep shock after the accident.

go into
He had gone into shock and was shaking violently.

be treated for